Handing environmentalists and congressional opponents of the proposed Keystone XL oil pipeline a new tool to fight the project, the Congressional Research Service (CRS) is estimating significantly higher greenhouse gas emissions from the project than the State Department found in its recently issued draft analysis.

Environmental advocates are already pointing to the March 15 CRS report as being more “balanced” than the department’s draft environmental impact statement (EIS). Environmentalists welcome the research service’s methodology because, unlike the State Department, it does not assume that the oil sands will be developed regardless of whether the pipeline is built to transport the crude from Alberta, Canada, to the Texas Gulf Coast.

But industry advocates of the pipeline say the CRS report is flawed compared with the draft EIS because of this assumption, suggesting they will push back on any effort to use the study to argue against Keystone.

The dispute over the study all but ensures the CRS report will play a role in renewed debate over the pipeline once Congress returns April 8. The House Energy & Commerce Committee has scheduled an April 10 hearing in the power subcommittee to discuss H.R. 3, a bill that would approve the pipeline and limit legal challenges.

Meanwhile, Senate environment committee ranking member David Vitter (R-LA) and Sens. James Inhofe (R-OK), Deb Fischer (R-NE) and Roger Wicker (R-MS) are urging EPA to fight any effort by environmentalists to force a settlement setting binding deadlines for the agency to craft greenhouse gas trading rules should environmentalists sue over a lack of a response to their petition asking EPA to use various Clean Air Act powers to create climate trading programs.